Lifting-jack



(No Model.)

0. FISHER. j 'LIFTING JAOKl No. 298,568.

Patented May 13, 1884.

I M Q INVENTOR N. PETERS; Phololihe nphcr. Wad-inflow D. C.

UNITED STATES To ctZZ whom it may concern:

Be it known that I, CLARK Frsnnn, a citizen of the Unitedstates, residing in Trenton, New Jersey, have invented a certain Improvementin Lifting-Jacks, which I entitle a Duplex Jack, 7 of which the following is a specification. j

My invention relates to a class of well-known contrivances employed for hoisting cars, carriages, and other weights, and for retaining them at any elevation. This class is too well known to require further explanatory mention. I I v The object of my invention is the construction of a mechanically simple yet powerful lifting jack which can not only be operated with a trifling expenditure of force, but is also adapted to remain fixedly in any predetermined position;

A preferred form of a convenient embodiment of my invention is represented in the aocompanying drawings and hereinafter del scribed and claimed. a

In the drawings, Figure l is a central vertical longitudinal sectional elevation through the entire apparatus, section being supposed upon the dotted lineman of Fig. 2. Fig. 2 is a top plan view of the entire apparatus. Fig.3 is a view in perspective of one of the toggle-bars re moved from the machine. Fig. l is a similar view of one ofthe trunnioned nuts, and Fig. is an illustrative detail of another form of ap paratus in which the upper extremities ofthc togglebars are connected by a toggle plate or link.

Similar letters of reference indicate corresponding parts.

In the drawings, A is the bed frame or plate of the j aok preferably a caststructure conveniently made in the form represented in the drawings-that is to say, as a laterally-walled structure, between the walls of which are formed two oppositely and preferably equally curved segmental toggle-ways, a. which constitute the interior floor of the frame. Gen trally within the bed-frame is cast or otherwise formed what I term a collar-socket, a, which is designed to contain and retain against endwise or axial thrust a collar fixed- 1y applied to the screw-shaft. V v

13B are two toggle bars or struts, a conven- Fries.

cLAnK FISHER," on TRENTON, NEW Jnnsnv.

LIFTING-JACK.

'ient form of one of which is shown removed from the machine in Fig. 3. These togglebars are, in the form of apparatus represented in Figs. 1 and 2, united as to their upper eX- treinities by a togglepin, b, upon which pin is hung or framed the lifting-head C of the jack. The feet 11* of the toggle-bars'rest, respect-ively,upon the bed-frame in its. segment al toggle-ways, as will be clearly understood by reference to the drawings, and these feet are provided with bearings b, or are other-' wise conformed to receive the trunnions d of the trunnioned nuts D, which latter are respectively mounted upon the respective extremities of the actuating screw-shalt E. The said actuating screw-shaft E is, as to its respective extremities, out with a right and a left hand thread, and as to its central portion, which is intermediate between its threaded portions, it is provided with a fixed collar, 6, which is housed within the collar-socket a of the bed-frame, or is otherwise-by means, for ii'istanoe, oflugs, projections, or kindred contrivances-retained in a fixed position with respect to the bed-plate, so as to prevent the axial movement of said screw -shaft. The screwshaft, as stated, is equipped with a nut upon each of its respective extremities, which nuts respectively engage the feet of the toggles, preferably to permit the movement of the togglebai's by means of their trunnions in the manner rcpresentedin the drawings. The feet of the toggle-bars are also provided with studs b, which are clearly represented in Fig. 3, and which, as'to their inner extremities, overhang the trunnions of the nuts and serve to retain said trunnions in their bearings, and as to their outer extremities travel in segmental guideways a correspondent in curvature to thetoggle ways formed in the inner faces of the side walls of the bed frame, thereby retaining the feet of toggle-bars, to prevent them from lifting out of the bedframe. The screwshaft, as to either or both of its extremities, is adapted to be provided with a lever, F, formed either as a simple turningdcey or as a ratcheted lever, through the instrumei ltality of which, or of any equivalent contrivance, rotation in the desired'direction is imparted to the screw-shaft.

'Sueh being a description of what I consider ICO a good form of an inexpensive embodiment of my invention, it will be readily understood that the invention resides simply in the combination of two very old mechanical powers viz., the toggle-joint and the screw. Theprimary power which is utilized for the lifting resides, of course, in the toggle-joint, and not in the screw, since it is obvious that the togglebars might be brought into their successive positions for raising aload by using instead of the screw any equivalent mechanical contrivance for drawing together the feet of the said togglebars; but the screw is evidently the best mechanical contrivance for the purpose, not only from its great power, and from its simplicity and economy of construction, but because at any period of its rest after its rotation the togglefeet are secured in their then position. This is of manifest advantage when, in the raising of loads, it is desired for the time being to leave the load in agiven position between the lowest and highest points of elevation-as, for instance, in the raising of therails and ties of a railroad, for lining up the joints, and

where frequent interruptions from passing trains occur.

In jacks as heretofore constructed, so far as my knowledge extends, the load has rested directly upon the screw, rack, or hydraulicpiston, as the case may have been, or upon that contrivance which is itself raised and low cred. In my invention, on the contrary, the load always rests directly upon the bed frame or plate, whatever may be the angle which, for the time being, the toggle-bars have assumed, and the only office of the screw-shaft, or of any equivalent contrivance employed for the approximating or separating of the feet of the toggle-bars, is to change the angle of the bed-frame, although, as already stated, other contrivances operative to the same result may be employed in place of the said collar and socket.

NVhere the jack is intended for very heavy work, the friction of the toggle-feet due to their sliding, with the entire load upon them, upon the bed-frame will be so great that it will be desirable to interpose small rollers or wheels between these surfaces, and this is conveniently done by extending the trunnions of the nuts entirely through the side faces of their bearings within the toggle-bars, and equipping such prolonged shanks, which then serve as axles, with rollers or wheels. The vital point of my invention, however, resides the only function of which is,as already stated,

to change the angular position of the togglebars or to retain them in any desired position.

The object of making the toggle-ways of segmental form is to reduce the acuteness of the angle when the toggle is at its lowest point, making less strain upon the screw than if the surface of the bed-frame were in a straight horizontal plane. The vertical movement of the horizontal screw-shaft which this segmental structure of way necessitates is allowed for by excavating the bed-frame at its extremities, and by making the collar-socket of the requisite vertical depth. The screwshaft can be rotated to a sufficient extent to run the nuts and toggle-feet out of the bed-frame, so that the toggles and shaft can be together re moved from the frame.

Having thus described my invention, I claim and desire to secure by Letters Patent of the United States- I 1. The combination, to form a lifting-jack, of two toggle-bars, the upper extremities of which are connected and adapted to carry the load, a bed-frame upon which the feet or lower extremities of said toggle-bars rest and travel, and a right-and-left-handed screwshaft adapted conveniently, by means of trun- IOO nioned nuts, to act'against the lower extremitravel, a right-and-left-handed screw-shaft adapted conveniently, by means of trunnioned nuts, to act against the lower extremities of said toggle-bars and cause their approach or recession upon said bed-frame, and means for preventing the axial movement of said screwshaft, substantially as described.

3. The combination, to form a lifting-jack, of two toggle-bars connected at their upper extremities by a toggle-pin, and as to said upper extremities equipped with a liftinghead, a liftinghead, a bed-plate upon which the lower extremities of said toggle-barsrest and travel, and a right-and-left-handed screwshaft which is adapted to said toggle-bars in such manner that upon its rotation in one direction it causes the approach of the lower extremities of said toggle-bars, or in the oppotogglebars connected as to their upper extremities, adapted as to said upper extremities to sustain the load, and as to their lower extremities adapted to travel-in said segmental toggle-ways, and ascreW-shaft or kindred device housed in the bed-plate, and adapted to occasion the approach or recession of the lower extremities of said toggle-bars, substantially kindred retaining device housed in the bed plate, and means for 'occasioning the rotation of said shaft, substantially as set forth.

6. The bed-frame hereinbefore described,

provided with segmental toggleways and with the central collar-socket.

zeasse I :3

7. The bed-frame hereinbefore described, provided with the segmental toggle-ways, the collai socket, and the guideways.

8. In combination with a bed-plate upon which the feet of the toggle-bars rest and travel, toggle-bars provided with feet which rest and travel upon said bed-plate, and also provided with bearings in said feet, and nuts equipped with trunnions adapted to said toggle-feet, substantially as and for the purpose set forth. v

' 9. In combination with the bed-fran1e provided with guideways, the toggle-bars provided with studs adapted to said guideways, substantially as set forth.

In testimony whereof I have hereunto signed my name this 8th day of February, A. -D. 1884.

CLARK FISHER.

In presence of- SAMUEL BRAOKETT, CHAS. W. Enwnnns.

It is hereby-certified that in Letters Patent No. 298,568, granted May 13, 1884, upon' I the application of Clark Fisher, of Trenton, New Jersey, for an improvement in f Lifting-Jacks, errors appear in the printed specification requiring correction, as follows: In lines 101 and 112, page 2, the comma should be omitted after the word conveniently, and inserted after the word adapted; and that the specification should be read with these corrections therein to make the Letters Patent conform to the record of the case in the Patent Oifice.

Signed, countersigned, and sealed this 20th day of May, A. D. 1884.

M. L. JOSLYN, Acting Secretary of the Interior.

[SEAL] Gountersigned:

BENJ. BUTTERWORTH,

Commissioner of Patents. 

